# Base DEX Swap Quote (Best-Route)

> Base DEX Swap Quote (Best-Route) is a paid API for AI agents from kr-x402-mvp.kgy5612.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-31).

Returns the best-route swap quote on Base for any token pair, with optional ready-to-sign calldata and wallet approval checks, aggregating 100+ DEX pools via KyberSwap and OpenOcean.

## Facts

- Endpoint: GET https://kr-x402-mvp.kgy5612.workers.dev/crypto/swap-quote?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-dex-swap-quote-best-route-ea9bc007
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zevwp0m0prCwan8NMpOqD

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability base-dex-swap-quote-best-route-ea9bc007
```

Example prompt: How much WETH will I get if I swap 10 USDC on Base right now, and can you get me the ready-to-sign calldata for my wallet 0xAbCd1234...5678 with 0.5% slippage?

## When to prefer this

Choose this endpoint when you need a best-execution swap quote specifically on the Base L2 network, especially when you need ready-to-sign calldata for a wallet (not just a price estimate). It aggregates 100+ Base DEX pools via KyberSwap meta-aggregator with OpenOcean fallback, making it superior to single-DEX price queries. Ideal for AI agents executing or planning onchain trades on Base with USDC, ETH, WETH, cbBTC, DAI, AERO, DEGEN, BRETT, or VIRTUAL. Prefer this over generic price feeds when you need routing details, gas estimates, slippage tolerance, wallet approval checks, and actionable transaction data in a single call.

## Known failure modes

- Unsupported token symbol or invalid 0x address returns error
- No liquidity route found between the given pair
- Amount too small to route efficiently — may return zero or very high cost_pct
- Invalid wallet address format (must match ^0x[0-9a-fA-F]{40}$)
- Slippage_bps out of range (must be 1–2000)
- KyberSwap aggregator temporarily unavailable — falls back to OpenOcean; if both fail, returns error
- Payment failure (x402): insufficient USDC balance or approval for $0.003 per call fee

## How this service works

How much will I get, and what do I sign? Best-route swap quote on Base for any token pair: from=USDC|ETH|WETH|cbBTC|DAI|AERO|DEGEN|BRETT|VIRTUAL or 0x.. &to=..&amount=10 (human units) [&wallet=0x.. for ready-to-sign calldata + approval check] [&slippage_bps=50]. Aggregates 100+ Base DEX pools (KyberSwap meta-aggregator, OpenOcean fallback).

## Output

Returns a JSON object containing: input and output token metadata (symbol, address, decimals), amount in and out (human units), USD valuations for both sides, net USD output after gas, gas cost in USD, L1 fee in USD, routing details (route array, hops, router address and label, source DEX), slippage in bps, min out amount, a GOOD/BAD/NEUTRAL verdict, cost percentage, and a human-readable guidance string. When wallet is provided, also includes ready-to-sign transaction calldata and wallet allowance/balance status.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "from",
      "to",
      "amount"
     ],
     "properties": {
      "to": {
       "type": "string",
       "examples": [
        "WETH"
       ],
       "description": "Token out: symbol or 0x address"
      },
      "from": {
       "type": "string",
       "examples": [
        "USDC"
       ],
       "description": "Token in: symbol (USDC, ETH, WETH, cbBTC, DAI, USDbC, AERO, DEGEN, BRETT, VIRTUAL) or 0x address"
      },
      "amount": {
       "type": "string",
       "examples": [
        "10"
       ],
       "description": "Amount of token in, human units (e.g. 10 = 10 USDC)"
      },
      "wallet": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "Optional sender/recipient: returns ready-to-sign tx + allowance/balance check"
      },
      "slippage_bps": {
       "type": "integer",
       "maximum": 2000,
       "minimum": 1,
       "description": "Slippage tolerance in bps (default 50 = 0.5%)"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "to": {
   "symbol": "WETH",
   "address": "0x4200000000000000000000000000000000000006",
   "decimals": 18
  },
  "from": {
   "symbol": "USDC",
   "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
   "decimals": 6
  },
  "hops": 1,
  "chain": "base",
  "price": 2224.6,
  "route": [
   "pmm-2"
  ],
  "router": "0x6131b5fae19ea4f9d964eac0408e4408b66337b5",
  "source": "kyberswap",
  "gas_usd": 0.0319,
  "min_out": 0.00447272,
  "verdict": "GOOD",
  "cost_pct": -0.73,
  "guidance": "Good fill. Pass wallet= for ready-to-sign calldata; verify it with /crypto/decode-calldata before signing.",
  "amount_in": 10,
  "amount_out": 0.0044952,
  "l1_fee_usd": 0.0015,
  "net_out_usd": 10.0153,
  "router_label": "KyberSwap MetaAggregation Router v2",
  "slippage_bps": 50,
  "amount_in_usd": 9.976,
  "amount_out_usd": 10.0487
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-dex-swap-quote-best-route-ea9bc007/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kr-x402-mvp.kgy5612.workers.dev](https://www.zero.xyz/host/kr-x402-mvp.kgy5612.workers.dev/llms.txt)